Solvent extraction apparatus and method



4 Sheets-Shani;

' INVENT RS.

I III Dec. 22, 1953 v R P HUTCHINS ETAL SOLVENT EXTRACTION APPARATUS AND METHOD Filed March 21 1950 4 Sheets-Sheet 2 R P HUTCHINS ETAL SOLVENT EXTRACTION APPARATUS AND METHOD Dec. 22, 1953 Filed March 21,

Dec. 22, 1953 R. P. HUTCHINS ET AL 2,663,624

SOLVENT EXTRACTION APPARATUS AND METHOD Filed March 21, 1950 4 Sheets-Sheet 3 Dec. 22, 1953 R. P. HUTCHINS ET AL 2,663,524

SOLVENT EXTRACTION APPARATUS AND METHOD Filed March 21, 1950 4 Sheets-Sheet 4 A l lA MA v TT vv 7 22 J 7 Patented Dec. 22, 1953 SOLVENT EXTRACTION? APPARATUSAND. METHOD Ralph, 1?, Hutchins and Forrest C. Simon, Piqua, Ohio, assignors to The French Oil Mill, Machinery Company, Piqua, Ohio Application March; 21, 1950, Serial No. 151,012

14 Claims.

1. This invention relates to solvent. extraction and more articularly to solvent. extraction in which the solids to be, treated are carried in open top, perforated bottom, drainage baskets in an.

elongated, endless path during which a solventcontaining liquid is. passed repeatedly through the solids in the baskets. Heretofore in. basket type extractors, the baskets were commonly carried in a vertically elongated path and the apparatus, if of substantial capacity, necessarily was rather tall, usually occupying more than one floor. Tall apparatus must be built quite rigid and, therefore, the cost of the. a paratus has been relatively high. Special, buildings. were sometimes necessary to accommodate the tall apparatus.

An. object of' this inv nti n. is to provi e. an improved method and apparatus for solvent extraction which will against prior methods and apparatus for basket type solvent extraction, which willutilize a, relatively low cost installation, which may be 011-. erated as a one floor system, with which the extraction apparatus .or equipment may be. preassembled at the factory, and unloaded and placed on the customers previously prepared concrete foundation, and which may utilize relatively cheap prefabricated buildings for housing the equipment.

Another object of the invention is to provide an improved and efiicient method and apparatus for solvent extraction, which will require a minimum ofsupervisory attention, which may be made largely automatic andcontinuous in operation. and which is inexpensive.

Another object of the invention; is to provide an improved solvent extraction apparatus of the basket type, which will be efficient in operation, which will have its; various partseasily accessible for servicing, which will be relatively low in height, which enables one to obtain the benefits of continuous miscella filtration in the baskets without interference with the extraction, in which the effectiveness of the extraction will be a maximum, and which will be relatively-compact, simple, efficient, trouble-fre and inexpensive.

Other objects and advantages will be apparent from the following description of one embodiment of the invention, and the novel features I will be particularly pointed out hereinafter in connection with the appended claims.

In the accompanying drawing:

Fig. 1. is a side elevation, on a reduced scale, of apparatus constructed in accordance with this invention;

overcome the. objecti ns Fig. 2 is a longitudinal, sectional elevation on a somewhat larger scale, of one end portion of theapparatus shown in Fig. 1;

Fig. 3 is a longitudinal, sectional elevation through the opposite end of the apparatus;

Fig. 4 is a plan of some of the hydraulic controls, and

Fig. 5 is a transverse, sectional elevation through the charging and unloading end of the apparatus shown in Figs l, to 3, the section being taken approximately along the line 5-5, Fig. 2.

In the illustrated embodiment of the invention, the apparatus includes a housing. I which is horizontally elongated and suitably mounted on base pedestals 2. This housing I may be, and usually is formed of a structural steel frame with sheet metal panels attached tothe frame and forming the enclosing walls of the same. Supported by the frame within the housing, at opposite ends thereof, are shafts 3 and 4 which are rotatably mounted in the housing frame.

Fixed on the shaft 3. are a pair of sprocket wheels 5, spaced apart along and concentric with the same. Similarly, a pair of sprocket wheels '6 are concentric with, spaced apart along and fixed to the shaft 4.

A pair of sprocket chains 1, one at each side of the housing, extend between the run over the sprocket wheels 5 and 6 at each side of the housing. The sprocket wheels and the chains form an endless, closed loop carrier which is orizontally elongated. The bearings id for the ends of shaft 4 are adjustable lengthwise of the housing to loosen or tighten the endless loop carrier. 'The shaft 3 carries a sprocket 8, Fig. 1, which is driven by a chain 9 from a chain Ill, fixed upon the shaft ll of a gear reducer of an electric motor [2. The motor thus serves to driv the shaft 3 at a slow, continuous rate and thus cause endless loop travel of the chains.

The motor I2 is mounted in a frame I3, and mounted on this frame 13 is a suitable hydraulic control mechanism I (see Fig. 4), having a rotatable cam shaft I 5 carrying a sprocket It. The motor shaft H also carries a chain which operates an endless belt I! that runs over the sprocket IS on the cam shaft I5. Fixed on the shaft 15 are a plurality of cams It, the peripheries of which operate valve stems 20 of the valves 2| in a desired, timed sequence and for desired durations. These valves 2|, when operated; pass an operating fluid, such as compressed air or an operating liquid, to operate hydraulic motors that operate certain controls of the apparatus, as will be explained later herein.

A plurality of drainage baskets 22 are arranged in succession along and between the sprocket chains 1, and supported between corresponding parts of the chains, as shown in Figs. 1, 2 and 3. Each basket is provided at each end with a supporting stud 23, the studs at opposite ends of each basket being axially alined and pivotally supporting the basket from the chains. Each basket is thus individually and rockably supported by the chains that form the endless carrier, and are free to pivot upon horizontal axes as they travel with the chains in a horizontally elongated, endless loop path. Each chain carriers rollers 24, Fig. 5, arranged at intervals along its length, which roll upon shelves 25 provided on the inside walls of the frame of the housing so as to support the chains against sagging in both upper and lower stretches while passing between the sprocket wheels 5 and 6.

Each chain also carries pins 26 midway between the studs 23, and pins 25 and rollers 24 are received in the notches Zl in the sprocket wheels 5 and 6 to provide a driving connection between them. Each end of each basket is also provided with three projecting pins Zia arranged in an equitriangular spacing about the adjacent stud 23. When the baskets are upright, two of the pins 23a will be equal distances above a horizontal plane through the axes of studs 23, horizontally alined and disposed at equal distances from a vertical plane through the axis of studs 23. pin 21a. will be alined vertically with the adja cent stud 23. The inside face of the frame of the housing I is also provided with ledges or shelves 28 which extend horizontally, adjacent the upper and lower stretches of the carrier, and provide tracks on which ride the horizontally alined pins 21a of each basket end. The engagement of the horizontally alined pins 21 with the shelves 28 prevents lateral tilting of the baskets during their horizontal travel. Suitable means is also provided at the sprockets 6 to keep the baskets upright while descending from the upper stretch of the carrier to the lower stretch, as shown at the right hand end of Fig. 3.

Various ways have been devised for keeping baskets upright while descending at the sprocket wheels 6, and while any of them may be used, this is accomplished in the illustrated apparatus by supporting on the shaft 4, a pair of additional sprocket wheels 29 spaced apart along the shaft 4, with a sprocket wheel 29 adjacent each wheel 5. Each sprocket wheel as is somewhat smaller than the sprocket wheel 6 and it. is provided in' its periphery with notches 30, as shown in Fig. 3. The wheels 28 are driven by suitable gearing at about /6 the speed of sprockets 6. As each basket approaches the right hand end of the carrier, see Fig. 3, the lower pins 21a on the basket will move into peripherally spaced notches 30 of sprocket wheels 29, and when each basket is immediately above the shaft l, the lower pin 21a of that basket will be in the center of a notch 30. as shown in Fig. 3.

During continued rotation of the shaft 4 and the sprocket wheels 5 and 29, the lower pin 2m at each end of the basket will be camrned to the right in Fig. 3, so as to gradually right out of a notch 30, which causes a partial rotation of the basket on the axes of the studs 23, and during this movement the second of the two upper pins 21a on that end of that basket will slowly enter notches 30 which follow those in which the lower pins 21a, were engaged. As the rotation continues, the notches so will slowly rotate the The third basket through engagement with the pins Z'Eato keep the baskets upright, and as they move away from the sprockets 6 and 29 (see Fig. 3) the two upper, horizontally alined pins will again hold the baskets against rocking.

As the baskets in the lower stretch of the carrier approach the sprocket wheels 5, as shown at the left in Fig. 2, the shelves 25 will end before the baskets reach the sprocket wheels 5, in order that the baskets may be rotated about the axes of their studs 23 to invert them and empty their contents into a discharge hopper 32. Any suitable means may be employed for inverting the baskets over the hopper 33., but as shown, there is provided at each side of the housing a bump-- like cam member 33 having a cam surface 3% which is disposed in the path of travel of the lower pin 21a. of the basket at that side of the housing. As shown inFig. 2, as the upper or horizontally alined pins Zia on the ends of each basket leave the shelves 28 in the lower stretch. Each upper leading pin 21a on each basket will leave its related shelf 28 shortly before the lower pins 210. engage the cam surfaces 35 and, therefore, the leading pins 2111 will pass above the humps of the cam surfaces as as the lower pins Zia, are cammed backwardly and upwardly (counterclockwise in Fig. 2) by the surfaces 34. This causes that basket to move into a half inverted position, shown in Fig. 2, in which the leading pins 27a have moved down the trailing sides of the humps of the cam members 33 before the lower pins 21 reach the crests of the cam surfaces 34.

As that basket continues to travel bodily to the left in Fig. 2, the leading horizontal pins 21a which have reached approximately the bottoms of the cam surfaces 34, will engage with upstanding but inclined cam surfaces 35 that retard those pins 27a, so that continued movement of the basket will complete its inversion over the hopper 32. This places the second of the horizontally alined pins at each end of that basket uppermost, with the other pins 2111 at that end of the basket horizontally alined but below the chain. As that basket moved into this position, the single upper pin 21a at each end of that basket will move into notches or recesses 36 in the ends of radial arms 3! forming parts of spaced wheels 38 which are fixed on the shaft 3.

There is also a wheel 38 at each side of the housing. Each notch 35 is arcuately concave, and asa pin 2'! moves into the notch, the basket is held against further rotation about the axis 1 of its supporting studs 23. These inverted baskets will then be held against rotation on the axes of their studs 23 as they travel upwardly or ascend to the upper stretch of their travel. The travel of the baskets through a half-revolu tion with the sprocket wheel 5 will again place them upright as they enter upon the upper horizontal stretch of their travel. As the baskets reach the upper end of their ascent at the left hand end as in Fig. 2, the pair of pins 21a which are then uppermost will then move over the shelves 28 which keeps the baskets from tilting during their travel to the right hand end of the housing in Figs. 2 and 3.

A charging hopper 39, Figs. 1 and 2, is disposed above the baskets at the beginning of their travel in the upper stretch, so that when each basket is below the hopper 39, a measured charge of solids to be treated may be deposited in that basket. This charging operation is repeated each time a basket passes beneath the hopper "3.9; Any suitable charging means may be em aszshownby dash lines zi'nFig; 1, so as-toswing I together to stop now of solids that havepassed the swinging gates 40, or open and passtsolibls The shafts 4| are provided with operating arms '45 and 46' which. are pivotal-1y connected: by

link 41, so that when: the lever or arm 46' is rocked, the plates 40 will swing toward each other or apart depending upon the. direction which the arm '46 is rocked.

The arm 461 is. pivotal'l-y. connected bypin. 48 and a slot to a piston l' .of a hydraulicmotor 50 of the double acting typ.e,.and which is controlled by pipes and .52. that admit operating fluid to opposite ends of the motor '50.; fluid is vented from one end while ,fl'uid' under. pressure is admitted to the opposite end, as is usual in double acting, reciprocating hydraulic motors. The motor '50 is pivoted; to the frame to enable the pin 48' to move with the arm as it moves in a slight arcuate path as it rocks. Arms 53 :and 54" are fixed on the shafts 44. for the lower gates, and these arms. zarerpivotally connected by a link '55, so that when the arm 54* is rocked, the gates 43 will swing toward or from each other, depending upon the directionof rocking'of the arm 54.

A hydraulic motor 55a is pivotally mounted and provided with a reciprocating piston 56 that is pivotally connected by a pin 57 to the arm 54, so that reciprocation of piston 56. will rock the arm 54 and cause the gate plates 43 to-swing toward and from each other. The motor 55 is supplied with operating fluid alternately through pipes 58-and 59. The pipes 51, 52, 58 and 59t=lead to the valves 2|, shown in Fig. 4, so that at the proper intervals in the cycle of operation, the valves 2| will admit operating fluid alternately to the opposite ends of the motors 50- and 55, and thus operate the gates 40 and-43 in the. proper sequence to. measure uniform charges of the solids to be treated and deposit them in succession in, the .basketsas they'move .one after another into proper position beneath the hopper 39.

Disposed above thebaskets as they travel jhori zontallyin the upper stretch are a plurality of distributing pans 60, 61, 2, '53:, :64 and 5 arranged end to end in succession. Another series of similar distributing pans i8; '5'! and 6.8 are arranged in end to end. succession above the baskets in the initial part of the lower stretch of their horizontal travel as shown in- Fig. 1'. Each of these distributing pans 60438 inclusive, is provided with a bottom 69, see Fig; 5, which undulates from side :to' .side so as to: provide a plurality of shallow troughs or grooves iii that run or extend parallel to the directionoi traveler: the baskets. These grooves '19 are arranged side by side in a direction from side to side of the housing, and thexbottomof eachgroove is provided with apertures spaced apart lengthwise of the groove. Thus, when liquid is placed in each of these pans, it will be discharged as a plurality of small streams distributed approx-i mateiy uniformlyover the entire bottom area of the pan, :so as-to produce the effect of a. con! The 6 tinuousrainof liquid over thebasketsas thef travel beneath the :pans. 'I'hecaiaacityofieach panand: of the apertures in thebottom thereof is sufiicient to keep the baskets flooded and sup ply the liquid faster than it can drain out, fora: purpose which. will-appear herein later.

A pair of spray pipes ll (Fig. 2), arranged in side the bottomv part of the hopper- 39 extend crosswise of the direction of" travel ofbaskets beneaththe hopper... These pipes 7H have a plureality of downwardly opening apertures along their. lengths that discharge streams or liquid downwardly from the bottom of the charging hopper es into any basket beneath it.v These pipes. "H are' individually controlled by valves "52, .Fig. 1, and connected to .a. .conunon-wsupply pipe T3;

Disposed below the baskets during their horizontal travel in the upper stretch are a row. of. collecting pans l4, Hand 76 abutting endito-end, and similarly arranged below the baskets in'atheir horizontal travel in the lower stretch and below thed'escendingbaskets are similar collectingzpans 11', I8 and 19, alsodi'sposed end to end Thepan Mfextend's to the discharge or unloading hopper 32. Each collecting pan M1 to 79 inclusive, has-a depressed bottom so as to drain: any liquid falling therein to an outlet pipe. A pipe 80 drains liquid from the bottom of the pan 14, a pipe 81: drains liquid from the bottom of pan 15, a pipe 82' drains liquid from the bottomof' pan l5 .andta pipe "83 dra-insl'iquid from the bottom of pan 1 1, a pipe 84- drains liquid" from the bottom: of pan Tiland' a pipe'85: drains liquid from the bottom of panwa The. pipe 80', which receives liquid from 'thebottom of the first collecting pan M leads towthe intake side of a motor operated pump 66. At its output sidethe-pump as isccnnect'ed to a: vertically extending pipe 8-! which 'is provided at itstop with branches 88 and 89, the branchtB -discharg ing into the distributing pan 6i) and the branch 89 discharging intothe distributing 1312:1151;

Branch 88 is control'led-by'a valve St'eandbra-nch' Sill'iscontrolled by a valve 91%. The pipe 81 which drains liquid from the second collecting pan "T51 is connected to the intake side or a motor driven pump 52, and the outputside of that punrp is.-connected' to a pipe $3 which extends to the" top of the housing and is there-provided with branches 94' and Q5; The branch ea, control-ledby avalve 8t, discharges into-the distributing pan. 52-, and the'branch 95, which s controlled by avazlveflefl', discharges into the distributing pan The pipe 82, which drains liquid" from the collecting. pan i6, is connected to the intake side of a motordriven pump Silyand a pipe es, which isconnected to the outputsideofa motor drivenpump 98 con tainsa valve Sta in series therein-and discharges into the distributing pan 6A.

The-pipe 8 3 which drains liquid from the oi the lowercollectingpans 'iifis COIll'lfiCiiEdtOathG intake side of a motor driven pump mil, tothe output side of which is connected a pipe EH that contains a branch it? controlled by a valve I03 that discharges into the distributing pan 55;. An otherloranch Hill is connectedto the pipe 13 that supplies the spray pipes H. The branch "554: is provided with a controlling valve which is operated by a hydraulic motor 585. A pipe lil'l leads from motor 185 to one of the valves ,21. shown :in 'Fig. t. The branch its also, before it reaches the valve 1%, is provided with another branch 1 08' which. leads to a filter (not shown) provided on the top of the housing, in which any 5 suspended so'lids in the liquid. delivered by the branch I08 may be filtered out. The liquid passing through the filter is then treated to recover the solvent and separate it from the extracted material, as usual in the solvent extraction process, but which is not illustrated and described herein, since it forms no part of the present invention.

The pipe 84 which drains liquid from the bottom of the collecting pan I8 is connected to the intake side of a motor operated pump I09. A pipe I I0, which is connected to the output side of pump I09 discharges liquid into the distributing pan 61, and through a branch III also into the distributing pan 6B. The pipe 85 which drains liquid from the pan 18 is connected to the intake side of the motor operated pump H2, and a pipe II3, which is connected to the output side of the pump H2, discharges the liquid into the distributing pan 68.

Fresh solvent from a suitable storage tank is. conducted first through a heater, not shown, where it is heated and then delivered by a pipe I I4, controlled by a valve I I5, to two branch pipes H6 and I I1. Valve I I is operated by a hydraulic motor I58 which, in turn, is operated by a fluid under pressure supplied by a pipe I I9 from one of the valves 2| of Fig. 4. Pipe I I6 has a regulating valve I20 and pipe I I! has a regulating valve I2 I. The pipe IIfi extends horizontally across the top of the basket 22 just before it reaches the inverting mechanism, Fig. 2, and has a plurality of downwardly opening apertures arranged in a row along its length in the portion above the baskets, so as to discharge a spray of liquid downwardly into any basket beneath it. Similarly, the pipe I I1 extends horizontally across the interior of the housing and above the baskets passing beneath just before they pass beneath the spray pipe I IS.

The operation of the illustrated apparatus will. now be described.

With the motor I2 operating, the shaft 3 will be positively and continuously rotated at a slow rate, preferably one which will move the baskets from about one to three feet per minute. This rate of travel is such that one basket cycle is completed in from about one to two minutes. The solids to be treated are supplied continuously through the conduit 42 to the charging hopper 39, and the hydraulic motors 50 and 550. are operated by the valve mechanism of Fig. 4 in timed rela tion to each other and to the travel of the baskets, so as to discharge a measured charge of solids into each basket below the hopper 39. The valve is operated by one of the cam controlled valves 22 of the master control mechanism shown in Fig. 4, so that just slightly prior to the operation of the gate plates 43, the valve I05 will be opened to deliver solvent-containing liquid from the pump IEO to the pipes 'li into the basket, and this dis charge continues while the basket is being filled and for a short interval after it is filled.

The discharge of liquid into the basket beneath hopper 1 9 through pipes II is faster than the liquid can drain out of that basket through its perforated bottom, with the result that a considerable amount of free liquid will be retained within the basket before the charge begins to enter. The solids are therefore discharged into a body of liquid in the basket, with the how continuing during charging, and while the solids are heavier than the liquid displaced thereby, they will be buoyed up by the liquid to such an extent that they will not settle and pack tightly in the bottom of the basket. Packing of the solids would reduce the flow of liquid through the mass. The liquid draining from this basket will be collected in the pan hi. After the basket has been filled and has largely moved out of charge receiving position, the valve I l-5 closes until another basket has moved approximately into charge-receiving position beneath the hopper 39. The valve I 05 is then again opened to place a pool of liquid in the basket into which another charge of solids to be treated is delivered. This cycle of operation is repeated as each basket comes beneath the hopper 39.

As the baskets move under the pan 60, which is very shortly after they leave a position beneath the hopper 39, they will receive a rain of further solvent-containing liquid that will con tinue throughout their travel beneath the pans Elisuccessively. The rate of fall of the liquid in this rain is faster than the liquid can drain from the bottoms of the loaded baskets, and this will keep the loaded baskets flooded with the liquid so that the solids in each basket will be buoyed up enough to prevent packing tightly. This permits maximum flow of the liquid through the mass of solids in each basket, and the flow of liquid through the contents of the baskets will be fairly uniform across the entire top face area of this basket, thus increasing the efficiency of the extraction. Some of the rain will fall between the baskets, but all will be collected in the collecting pans beneath the baskets in their travel.

It will be noted that the liquid from the pan it will be delivered partly to the pan 5% and partly to the pan 65 so that some or". the liquid passing between the distributing pan (iii and the collecting pan M will be advanced to the pan iii and drain into the next collecting pan 5. The liquid collected in the pan "i5 will be delivered partly to pan which will drain into pan :5, and partly into the next pan 5.3 from which it drains into the next pan 7%. Thus the solventcontaining liquid will gradually progress from distributing pan to distributing pan throughout the entire upper stretch of the travel of the baskets until the pan is reached. The pan G5, which is over the descending baskets, receives its supply of solvent-containing liquid from the pan Tl into which it again drains. The fresh, solvent containing liquid in heated condition is sprayed into the baskets while in two posh tions just before they reach the inverting positions under the control of the valve H5. Valve H5 is controlled from one of the valves 2i in timed relation to the travel of the baskets.

This fresh solvent is delivered intermittently so that a charge is given into each basket only While the basket is immediately below the pipes H5 or Hi. This prevents waste or" the fresh. solvent-containing liquid. This fresh, solventcontaining liquid, after passing through the baskets, which are in the positions just before the baskets are emptied, drains into the pan l where it is collected and forwarded to the lasting distributing pan 58. The liquid from pan 558 falls as rain on the baskets passing beneath it, and substantially all of it will be collected in the pan l'ii. From pan E3 the liquid will be delivered to the pans B6 and 61. Thus, the solvent-containing liquid will gradually progress along the housing from basket to basket concurrently with the travel of the baskets in the upper stretch but in a countercurrent direction relatively to the travel of the baskets in the lower stretch.

The fresh solvent which is added to the baskets just before the baskets are inverted and 9 washes oil fromythe: solids substantially all'of the solvent-containing liquid which carries in solu- -tion'the component parts that were to be extracted so that the solids at the ti'me they are emptied into the hopper 32 will be wet with only substantially pure solvent, and with very little or no solvent which carries therein any of baskets at the time of filling and part of it passed to the' filt'er wheresolids suspended in the l-iduidare'reinove'd', and then the dissolved coinpone'nt is separated from the solvent. The a rhbuht' f This 68118 01 SOIVIit-Cdhtdihillg liqiiid removed through the-filter will, of course, vary directly with the amount of the fresh solvent which is-de1i-vereatnrough the pipe n]; Itwill be noted that the litlu'id is repeatedly passed through the baskets SO' that the solids in each *ba'ske't function as stp by step-filters and remove "iilista'ritially alldine-s'olid's that may be carried infsus'peiision the-solvent containing liquid or 'rnisc'ella The'progi-essianef thefsolveiit-containing liquid oi mis'cellaja ilongthe upper stretch of the X- 'teriohis concufrent with the travel of the hasli'et's; and dui-in'gthis' concurrent travel the highest' concentrated niiscella and solids with the highest concent ation or the oil therein are in moving contact with each other and travel along together. wehave round by experience tha't the strehgth of the In iscella Or the" ai'n'bui'it or X- tracted o'il containedinthe solye'nt of'therniscella-h'a'sno appreciable eirect'u on the extracti'n'g' power ofthe solv'eht up" to concentrations of oil as high as to Asares'iil-t, the concurrent cyclethus provided has maximum effectiveness for extraction, andin addition, we are able'to filter thismiscella through the solids'of the baskets before-the 'miscella is p'uinpe'd'to the final filter. This filter on" top" of the" housing is really only a safety filt'e'r, because "sill-listanti'ally all filtering of the" misc'ella-i's donein the bask'ets during the extraction.

Attention is called to the i'ac't that just" asthe solids are dropped into the basket throughe hopper-39', asiib'st'antial amount semis-a ua is deposited in-thehasketso as to provide' a substantial body of liquid in the basketwhich builds up since itis'sup'plie'd' faster thah'itcan drain out? When the solids from thef-=hoppen39 fall into this body of 'misc'ella already indie-basket, they will be buoyed :up by the liquidniis'cellaso that they ,willnot" tightly pack together. "By ke'eping thebasketsin a flooded state ith'e solids will rem-aindn' a ve'ry"loose and uniformielation inthebaskets; due ,to the buoyancy ofthe miscella. ,This' application of excess" miscell'a is continued around the" first turn'of" the exterior and, Joymaintaining this liquid level the baskets at all times, we have" found that' imp'rove'd extraction and-increased capacity areobta'ine'd. jieretoiore, when a liquid'l'evel was not maintained in the baskets and the baskets were allowed to drain ful-lygthe-solids the basliets or travel untilthey r p where'hy tightpackingfofthe solids'ineachh lret packed rather densely .and tightly,gwhieli not only restricted the full flow capacity through the baskets; but also .u'noertainly afiected theweffi'ciency of the extraction, since on'ly a rather limited quantity of the solvent could, drain through the solids in theoasket, and flow through the solids was uneven, due to eharineling. By

keeping thabaskets flooded with the ,miscella during substantially allof their traveljro r the loading. .position to close to unloading position, it isiposs'ible to .pass a .maximum a1 nount Of,,.. Qlventthrough thesolidsin a given lengthof travel. This has resulted in an increased thoroughness of extraction and maximum extraction capacity.

It ,willhe understood that various changes in the detailsand arrangements of part whichhave been herein described and illustrated in order to explain ,thenature offlthe invention, may he made by those skilled insthe art, within the principle and scope of the invention as expressed in the appended. claims.

Weclaim: ..1- -.A hor z nta basket y ,..s .v n ex rac compri in a ho n an less,mov hleqa i within said h usin a d havin re a v ly lon anflj raie t pp randl w r tr tches connected y r lat el .s o s mi-c c lar, as nd n ar d descending end sectionspa r ta ab e sun srt .fo

en a n a d pp rti e nd se tion. an through it supporting said, carrier, individually pivoted, open top,perforatedbottom, drainage baskets supported by and movable with. said carrier in an; endless loop path, a charginghopp'er disposed above the baskets at the start of the upper stretch of their travel; for depositing solids in measured charges into saidbaskets in succession, an inverting device disposed adjacent its lower stretch. near the ascending end section for engaging and inverting said baskets in succession to empty them near theend of: the lower stretch of their travel, means carried by said housing and said support'and engaging the baskets in their ,traveliromthe. charging means to themverting means, for keeping them upright; said support for said ascending end section? engaging withtheinvertedbaskets and holding them from pivotingzon the carrier during their ascent by which they are uprighted, means having a discharge pipe for continuously introducing a'solven-t-containing liquid into the said basket charging position andkeeping it filled during charging, and circulatingin'eans for passing solvent=containing liquid downwardly thrdugh said filled baskets in'afguantity adciuatetokeepthem also ones with said 'liduid throughout their path each said invertinlm win be cont nuousl resisted by the buoyancy" or theliouid in that"basliet; H H 2'. In solvent extraction w i h the 5 91 j tbfe ii ih dhorytn idle treated ror; extra ion 1 that assthe soivent ontaiimg extraction liduid through said fil led' baslgets, that iinprovement which compris's directing into each of said basliets' in succession while they are in loadfngpdsiliq'uid'to prevent packing ofthe'solids the asl-the baskets from Y loadins osruon toward; uri- 11 loading position directing more of such extraction liquid into said baskets at a rate suiiflcientll faster than it can drain off through the bottoms of the baskets to keep the solids from packing by settling in the baskets.

3. In a solvent extraction method of the type in which the solids to be treated for extraction are conducted between loading and unloading positions in baskets with open tops and drainage bottoms, that move in an endless loop path and that pass the solvent-containing extraction liquid through said filled baskets, that improvement which comprises discharging said liquid into the basket in leading position before and during filling of each basket faster than it can drain out, to prevent packing of the solids delivered into the basket in loading position, and delivering solvent-containing liquid continuously into said loaded baskets until they closely approach unloading position, at a rate faster than it can drain out of the baskets so as to keep the solids flooded with the said liquid.

4. In a solvent extraction method of the type in which the solids to be treated for extraction are conducted between loading and unloading positions in baskets with open tops and drainage bottoms, that move in an endless loop path and i that pass the solvent-containing extraction liquid through said filled baskets, that improvement which comprises flooding the baskets just before and during their loading with solids with solventcontaining liquid, keeping the loaded baskets flooded with said liquid for the major part of their travel toward unloading position, and during the latter and final part of their travel toward unloading position, flooding the baskets with fresh solvent-containing liquid.

5. In a solvent extraction method of the type in which the solids to be treated for extraction .are conducted between loading and unloading positions in baskets with open tops and drainage bottoms, that move in an endless loop path and that pass the solvent-containin extraction liquid through said filled baskets, that improvement which comprises flooding the baskets just before and during their loading with solids with solventcontaining liquid, keeping the loaded baskets flooded with said liquid for the major part of their travel toward unloading position and during V the latter and final part of their travel toward unloading position passing fresh solvent-containing liquid through the baskets.

6. A horizontal basket type, solvent extractor comprising a housing, an endless carrier in said housing and having relatively long upper and lower straight stretches and relatively short ascending and descending end portions at the ends of said stretches, a pair of sprocket wheel units, one at each end of the upper stretch and around which the carrier runs in passing from one of said stretches to the other, a plurality of drainage baskets having open tops and apertured bottoms individually and pivotally attached to said carrier in succession and moving therewith, a delivery hopper for delivering measured charges of solids to be treated into said baskets in succession as they start travel with said carrier along said upper stretch, an inverting cam disposed in the path of travel of said baskets adjacent the end of said lower stretch and inverting the passing baskets in succession to empty them, a holder engaging with the inverted baskets and holding them from pivotal movement on the carrier as they move with the ascending portion of the carrier to the starting end of the upper stretch, during which they are uprighted, spray head's arranged in rows above the baskets as they travel along the upper and lower stretches for delivering solvent liquid into the open tops of said baskets in succession, a plurality of pans arranged in succession beneath the baskets carried by the upper and lower stretches up to said cam, a source of fresh solvent liquid connected to the last of said spray heads beneath which the baskets pass just before engaging with said cam, a pump connected to said pans to remove solvent liquid collecting therein and deliver it to other of said spray heads, so as to circulate the solvent liquid through said baskets repeatedly, and a driving connection to one of said sprocket wheel units for rotating that unit and through it moving said carrier and baskets.

7. A horizontal basket type, solvent extractor comprising a housing, an endless carrier in said housing and having relatively long upper and lower straight stretches and relatively short ascending and descending end portions at the ends of said stretches, a pair of sprocket wheel units, one at each end of the upper stretch and around which the carrier runs in passing from one of said stretches to the other, a plurality of drainage baskets having open tops and apertured bottomsindividually and pivotally attached to said carrier in succession and moving therewith, a delivery hopper for delivering measured charges of solids to be treated into said baskets in succession as they start travel with said carrier along said upper stretch, an inverting cam disposed in the path of travel of said baskets adjacent the end of said lower stretch and inverting the passin baskets in succession to empty them, a holder engaging with the inverted baskets and holding them from pivotal movement on the carrier as they move with the ascending portion of the carrier to the starting end of the upper stretch, during which they are uprighted, spray heads arranged in rows above the baskets as they travel along the upper and lower stretches for delivering solvent liquid into the open tops of said baskets in succession, a plurality of pans arranged in succession beneath the baskets carried by the upper and lower stretches up to said cam, a source of fresh solvent liquid connected to the last of said spray heads beneath which the baskets pass just before engaging with said earn, a pump connected to the last pan below the baskets that approach said inverting cam to remove therefrom solvent liquid and deliver it to the spray head above the baskets over the next to the last pan before said inverting cam, other pumps connected to each of the other pans to remove liquid therefrom and deliver it too. spray head, and a driving connection to one of said sprocket wheel units for rotatin that unit and through it moving said carrier and baskets.

8. A horizontal, basket type, solvent extractor comprising a housing, an endless, movable carrier within said housing and having relatively long and straight upper and lower stretches connected by relatively short end sections, a plurality of open top, perforated bottom drainage baskets individually pivoted to, supported by and movable with said carrier in an endless loop path, a pair of wheel units, one at each end of the loop, around which the end sections of the carrier pass in changing from one stretch to the other and with the diameter of each wheel unit corresponding to the distance between the stretches of the carrier, a drivin connection to one of the wheel units for rotating it and through it movi'ng said carrier in said path, a hopper device'dis posed above the basket'atthe-start of-the upper stretch, and beneath which the baskets pass in near the end of their travel in the. lowerstretch and engaging said baskets in successionand inverting them to empty them, guides along the upper and lower stretches prior to saidcam for keeping the baskets from rocking, aholding device movable with the. wheel unit at. the descending end of the carrierfor'keepingthe baskets upright as they descend from. the upper stretch tov the lower stretch,. a holder moving with said wheelv unit at the'ascending endof the carrier, engaging with the inverted: baskets. at the end of the lower stretch andholding them from pivotal movement on. the carrier during their ascent tothe-upper stretch of thetloop. path,

which uprights the baskets during their: ascent, pans arranged end to. end below the baskets in said upper stretch, and below the lower stretch up to said cam, spray heads disposed above the baskets in their travel with the upper stretch of the carrier and also above the baskets in their travel with the lower stretch of the carrier up to said cam to spray a solvent liquid into said baskets, apump connectedat its intake side with :each pan to remove liquid collectingtherein, a connection from the delivery side of each pump to one of said spray heads to circulate said solvent liquid over solids insaid baskets repeatedly, and a source of fresh solvent liquid connected'to the lastspray head-beforethe cam.

9: A horizontahbasket type, solvent extractor comprising a housing, an endless, movable carrier within said housing: and having relatively long and straightupper and lower stretches connected by relatively short end sections, a plurality of open top, perforated bottom drainagebaskets individually pivoted to,,suppo'rted by and movable with said carrier in an endless loop path, a pair of wheel units, one at each end of the loop, around which the end sections of the carrier pass in changin from one stretch to the other and with the diameter'of eachwheel unit corresponding, to the distance between the stretches of the carrier, a driving connection to one ofthe wheel unitsfor rotating it and through it moving said carrier in said path, a hopper device disposed above the basketat the start of'the upper stretch, and beneath which the baskets pass in succession from the ascending end of the carrier, for depositing measured charges of solids to be treated into said baskets in succession, a cam disposed along the path of travel of the baskets near the end of their travel in the lower stretch and engaging said baskets in succession and inverting them to empty them, a holding device movable with the wheel unit at the descending end of the carrier for keeping the baskets upright as they descend from the upper stretch to the lower stretch, a holder moving with said wheel unit at the ascendin end of the carrier, engaging with the inverted baskets at the end of the lower stretch and holding them from pivotal movement on the carrier during their ascent to the upper stretch of the loop path, which uprights the baskets during their ascent, pans arranged end to end below the baskets in said upper stretch, and below the lower stretch up to said cam, spray heads disposed above the baskets in their travel with the upper stretch of the carrier and also above the 2, comprising a housing, .an

baskets in. their'itravel with the lower stretch of the carrier up to saidcam',..tosprayla solvent liquidinto said baskets, liquid. circulating systems withpumps connecting said spray heads andipansifor repeatedly circulating. a solvent liq:-.- uidithroughthe chargesof solidsiin said baskets, anda source of fresh solvent liquid connected tdthe last spray: head-before the cam;

10. A. horizontal, basket type, solvent-extracli) tor. comprising a housing, an endless movable carrier within said housing'a'nd-having relatively long. andstraight upper and lower. stretches con- (nected by. relatively short end sections, a plu rality of open top, perforated bottom drainage is baskets individually pivoted to, supported by and .movablewith saidcarrier in anendless looppath, a pair of: wheel units,;one at each end of the 'loop, .around-whichithe end-sections of the carrierlpass in changing from one stretch to the other and .with the'diameter of each wheelunit corresponding .to the distance between the "stretches of the carrier, a driving connection to one of thewheel e-units for rotating. it and through it mo'vingisaid carrier in said-path, a hopper device disposed above the basket at the sta'rt of the'upperstretch, and beneathwhich the baskets pass in succession from the ascending. end of the carrier, for'depositing measured charges of solidslto lie-treated into said baskets in succession,-a1cam disposed along the path of travel-of the-basketsnear the end of their travel in the lower stretch and en,- gaging said baskets in succession and-inverting them to empty them, a-holdermoving with said wheel unit at the ascending end of the carrier 5 ,for engaging with the inverted baskets leaving said-cam and holding them against pivotal 'rooking on said carrier during their ascent to the upper stretch of theicarrier; which uprights them, pans arranged below the baskets on the upper'iand so lower stretches of the carrier and arranged in end'to end relation in the direction-of travelgof the baskets, spray headsarrangedabove the-baskets which are above pans, a source of fresh {SQ}- vent liquid connected to one ofsaidsprayheads rto deliver fresh solvent liquid. thereto, and circulating means connecting the pans and spray ,heads to move the solvent liquid from pansto ispray headsiprogressi-vely ina selected plan;

11. A horizontal, basket type, solvent'extractor endless, movable carrier within said housing and having relatively long and straight upper and, lower stretches connected by relatively short end" sections, a plurality of open top, perforated bottom drainage baskets individually pivoted to, supported by and movable with said carrier in an endless loop path, a pair of Wheel units, one at each end of the loop, around which the end sections of the carrier pass in changing from one stretch to the other and with the diameter of each wheel unit corresponding to the distance between the stretches of the carrier, a driving connection to one of the wheel units for rotating it and through it moving said carrier in said path, a hopper device disposed above the basket at the start of the upper stretch, and beneath which the baskets pass in succession from the ascending end of the carrier, for depositing measured charges of solids to be treated into said baskets in succession, a 7 cam disposed along the path of travel of the baskets near the end of their travel in the lower stretch and engaging said baskets in succession and inverting them to empty them, a holder moving with said wheel unit at the ascending end of the carrier for engaging with the inverted above pans, a source of fresh solvent liquid connected to the last spray head over the baskets in the lower stretch, and a plurality of pumps, each of one group thereof being connected at its intake side to one of said pans below the baskets in said lower stretch and at its delivery side to said spray head over the next preceding pan below the lower stretch of the carrier, each pump of another group thereof being connected at its intake side of a pan below the upper stretch of .the carrier and at its delivery side to the spray head over the pan next along the upper stretch in the direction of travel of the baskets on the upper stretch of the carrier.

12. A horizontal, basket type, solvent extractor comprising a housing, an endless, horizontally elongated carrier within said housing, a rotatable wheel unit at each end of the housing with the carrier passing around said units for support and operation thereby, the carrier stretches between said units being straight, a plurality of open top,

perforated bottom drainage baskets individually pivoted to said carrier and arranged in succession along the carrier to move therewith in an endless loop path, a driving connection to one of said wheel units for rotating it and through it moving said carrier to carry said baskets in said loop path, a charging hopper disposed above the baskets at the start of their movement with the upper stretch of the carrier, and discharging solids to be extracted into said baskets in succession, an inverting device disposed at the end of the lower stretch of the carrier, engaging said baskets in succession and inverting them to empty them, a source of fresh solvent liquid, spray heads disposed above'and pans disposed below the baskets carried by the upper and lower stretches of the carrier from the charging hopper to the inverting device, and circulating means including pumps and said pans and said spray heads for passing said solvent liquid from said source downwardly and repeatedly through said baskets during their travel from the hopper to said inverting device, according to a selected.

16 plan of the order in which the solvent progresses through the succession of baskets.

13. A horizontal, basket type, solvent extractor comprising a housing, an endless carrier, a plurality of open top, apertured bottom baskets attached to said carrier in succession therealong, a pair of wheel units spaced apart horizontally and mounted for rotation about horizontal axes, said carrier running over said wheel units and having relatively long, straight upper and lower stretches between said units, the portions of the carrier running around said units being the ascending and descending end sections connecting said stretches, a driving connection to one of said units for rotating it and through it moving said carrier and baskets, a charging hopper for loading the baskets at the start of the upper stretch, an inverting cam in the path of the baskets at the end of the lower stretch for engaging and inverting the baskets as they pass, spray heads disposed in succession above the baskets in their travel along both upper and lower stretches from the hopper to the cam, pans arranged in succession below the baskets in both upper and lower stretches, and a plurality of circulating circuits including pumps and said heads and pans for creating a rain of solvent liquid from heads to pans along both upper and lower stretches of said carrier through which the baskets move from the hopper to said cam.

14. The extractor substantially as set forth in claim 13, said spray heads being containers having apertured bottoms undulating from side to side in a direction crosswise of the direction of travel of said baskets.

RALPH P. HUTCl-IINS. FORREST C. SIMON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 654,170 Malard July 24, 1900 813,078 Bernhardt Feb. 20, 1906 1,411,154 Bollmann Mar. 28, 1922 2,117,113 Engler May 10, 1938 2,225,799 Robinson Dec. 24, 1940 FOREIGN PATENTS Number Country Date 13,836 Great Britain June 13, 1912 507,465 Great Britain June 15, 1939 74,042 Switzerland Jan. 2, 1917 

2. IN A SOLVENT EXTRACTION METHOD OF THE TYPE IN WHICH THE SOLIDS TO BE TREATED FOR EXTRACTION ARE CONDUCTED BETWEEN LOADING AND UNLOADING POSITIONS IN BASKETS WITH OPEN TOPS AND DRAINAGE BOTTOM, THAT MOVE IN AN ENDLESS LOOP PATH AND THAT PASS THE SOLVENT-CONTAINING EXTRACTION LIQUID THROUGH SAID FILLED BASKETS, THAT IMPROVEMENT WHICH COMPRISES DIRECTING INTO EACH OF SAID BASKETS IN SUCCESSION WHILE THEY ARE IN LOADING POSITION, A SUBSTANTIAL QUANTITY OF SAID SOLVENT-CONTAINING EXTRACTION LIQUID, AND BEFORE SUCH LIQUID DRAINS OFF, DEPOSITING A CHARGE OF THE SOLIDS TO BE EXTRACTED INTO THE BASKETS CONTAINING SUCH LIQUID TO PREVENT PACKING OF THE SOLIDS IN THE BASKETS, AND DURING THE MAJOR PART OF THE TRAVEL OF THE BASKETS FROM LOADING POSITION TOWARDS UNLOADING POSITION DIRECTING MORE OF SUCH EXTRACTION LIQUID INTO SAID BASKETS AT A RATE SUFFICIENTLY FASTER THAN IT CAN DRAIN OFF THROUGH THE BOTTOMS OF THE BASKETS TO KEEP THE SOLIDS FROM PACKING BY SETTLING IN THE BASKETS. 